VI-RADS: Multiinstitutional Multireader Diagnostic Accuracy and Interobserver Agreement Study.

BACKGROUND. The Vesical Imaging Reporting and Data System (VI-RADS), based on multiparametric MRI (mpMRI), was developed to provide accurate information for the diagnosis of muscle-invasive bladder cancer (MIBC). OBJECTIVE. The purpose of our study was to evaluate the interobserver agreement and diagnostic performance of VI-RADS among readers with different levels of experience. METHODS. This retrospective study included 91 consecutive patients who underwent mpMRI before transurethral resection of bladder tumor (TURBT) from July 2010 through August 2018. After attending a training session, seven radiologists (five radiologists experienced in bladder MRI and two inexperienced radiologists) reviewed and scored all MRI examinations according to VI-RADS. The interobserver agreement was assessed by kappa statistics. ROC analysis was used to evaluate the diagnostic performance for MIBC. AUCs were estimated. RESULTS. Among 91 patients (72 men and 19 women; mean age ± SD, 73.2 ± 10.2 years), 48 (52.7%) had MIBC and 43 (47.3%) had non-muscle-invasive bladder cancer. Sixty-eight patients were treated with TURBT, and 23 were treated with radical cystectomy. Interobserver agreement was moderate to substantial (κ = 0.60-0.80) among the experienced readers, substantial (κ = 0.67) between the two inexperienced readers, and moderate to substantial (κ = 0.55-0.75) between the experienced and inexperienced readers. The pooled AUC was 0.88 (range, 0.82-0.91) for experienced readers and 0.84 (range, 0.83-0.85) for inexperienced readers, and 0.87 for all readers. Using a VI-RADS score of 4 or greater as the cutoff value for MIBC, the pooled sensitivity and specificity were 74.1% (range, 66.0-80.9%) and 94.1% (range, 88.6-97.7%) for experienced readers and 63.9% (range, 59.6-68.1%) and 86.4% (range, 84.1-88.6%) for inexperienced readers. Using a VI-RADS score of 3 or greater as the cutoff value, the pooled sensitivity and specificity were 83.4% (range, 80.9-85.1%) and 77.3% (range, 61.4-88.6%) for experienced readers and 82.0% (range, 80.9-83.0%) and 73.9% (range, 72.7-75.0%) for inexperienced readers. CONCLUSION. We observed moderate to substantial interobserver agreement and a pooled AUC of 0.87 among radiologists of different levels of expertise using VI-RADS. CLINICAL IMPACT. VI-RADS could help determine the depth and range of excision in TURBT, decreasing the risk of complications and enhancing the accuracy of pathologic diagnosis.

Segmental multicystic dysplastic kidney in an adult: usefulness of enhanced CT in excretory phase.

We present an adult case of segmental multicystic dysplastic kidney (SMCDK). The patient had a 10 × 6 cm oval-shaped mass consisting of a solid and multilocular cystic component at the right upper renal sinus. The solid component showed gradual and mild enhancement on dual-phase enhanced CT. Excretory-phase CT demonstrated the excretion of contrast medium into the septa and cysts. Dilation of the upper calices and renal pelvis and atretic renal pelvis in the mass were also clearly visualized in the excretory phase. The signal intensity of the solid component was slightly lower than that of the renal parenchyma on T2-weighted images and similar to that of the medulla on diffusion-weighted images. Right nephrectomy showed a multilocular cystic component within the renal sinus and some of the cysts contained blood. The renal pelvis of the upper moiety was blind, as suggested by CT. Microscopically, there were multiple non-communicating small cysts, as shown by CT, and the wall was lined with immature tubule-like cells. In addition, immature tubule-like cells were seen in the septa. Immature mesenchymal cells were seen around the cysts. The solid component mainly consisted of fibroconnective tissue with immature tubule-like cells. The pathological diagnosis was confirmed as SMCDK. Excretion of contrast media into the septum and cystic component might be a characteristic finding of SMCDK in addition to the finding of a multilocular cystic mass in the upper moiety with urinary tract abnormality.

Characteristics of MR Imaging for Staging and Survival Analysis of Neuroendocrine Carcinoma of the Endometrium: A Multicenter Study in Japan.

PURPOSE: This study aimed to examine MRI features and staging of neuroendocrine carcinoma (NEC) of the endometrium and evaluate survival. METHODS: Clinical data, pathological, and preoperative pelvic MRI findings in 22 patients with histologically surgery-proven endometrial NEC were retrospectively reviewed. Tumors were pure NEC (n = 10) or mixed histotype (n = 12), with 13 large and nine small cell type. RESULTS: International Federation of Gynecology and Obstetrics (FIGO) staging was I, II, III, and IV in 6, 2, 12, and 2 patients, respectively. In 13 (76.4%) of 17 patients with pathological deep myometrial invasion, MRI showed abnormal diffusely infiltrative high T2 signal intensity throughout the myometrium with loss of normal uterine architecture. All tumors had restricted diffusion (apparent diffusion coefficient map low signal intensity, diffusion weighted imaging high signal intensity). Accuracy of T staging by MRI for all cases was 81.8%, with reference to pathology staging, while patient-based sensitivity, specificity, and accuracy for detecting metastatic pelvic lymph nodes was 60.0%, 100%, and 77.8%, respectively. Two intrapelvic peritoneal dissemination cases were detected by MRI. During follow-up (mean 30.4, range 3.3-138.4 months), 16 patients (72.7%) experienced recurrence and 12 (54.5%) died of disease. Two-year disease-free and overall survival rates for FIGO I, II, III, and IV were 66.7% and 83.3%, 50% and 100%, 10% and 33.3%, and 0% and 0%, respectively. CONCLUSION: Abnormal diffusely infiltrative high T2 signal intensity throughout the myometrium with normal uterine architecture loss and obvious restricted diffusion throughout the tumor are suggestive features of endometrial NEC. Pelvic MRI is reliable for intrapelvic staging of affected patients.

Diagnostic Accuracy and Interobserver Agreement for the Vesical Imaging-Reporting and Data System for Muscle-invasive Bladder Cancer: A Multireader Validation Study.

A Vesical Imaging-Reporting and Data System (VI-RADS) based on multiparametric magnetic resonance imaging (mp-MRI) was developed to provide accurate information for the diagnosis of muscle-invasive bladder cancers (MIBCs). In this study we evaluated the interobserver agreement and diagnostic performance of VI-RADS. We retrospectively evaluated data for 74 consecutive patients with bladder cancer who had undergone mp-MRI before transurethral resection in a single institution from January 2010 to August 2018. Five readers assessed the probability of the presence of MIBC using VI-RADS scores. The interobserver agreement was assessed by measuring intraclass correlation coefficients (ICCs). Receiver operating characteristic (ROC) analysis was used to evaluate the MIBC diagnostic performance. The area under the ROC curve (AUC) was estimated for ordinal score assessments. Our study demonstrated that interobserver agreement was excellent among five readers (ICC 0.85, 95% confidence interval 0.80-0.89) and the diagnostic performance of VI-RADS was represented as a pooled AUC of 0.90 (95% confidence interval 0.87-0.93). PATIENT SUMMARY: We evaluated the interobserver agreement and diagnostic performance of a new scoring system based on magnetic resonance imaging called a Vesical Imaging-Reporting and Data System (VI-RADS) for muscle-invasive bladder cancer. Our results indicate that VI-RADS is suitable as a comprehensive tool for appropriate treatment planning for patients with bladder cancer.

A predictive diagnostic model using multiparametric MRI for differentiating uterine carcinosarcoma from carcinoma of the uterine corpus.

PURPOSE: To construct a diagnostic model for differentiating carcinosarcoma from carcinoma of the uterus. MATERIALS AND METHODS: Twenty-six patients with carcinosarcomas and 26 with uterine corpus carcinomas constituted a derivation cohort. The following nine MRI features of the tumors were evaluated: inhomogeneity, predominant signal intensity, presence of hyper- and hypointense areas, conspicuity of tumor margin, cervical canal extension on T2WI, presence of hyperintense areas on T1WI, contrast defect area volume percentage, and degree of enhancement. Two predictive models-with and without contrast-were constructed using multivariate logistic regression analysis. Fifteen other patients with carcinosarcomas and 30 patients with carcinomas constituted a validation cohort. The sensitivity and specificity of each model for the validation cohort were calculated. RESULTS: Inhomogeneity, predominant signal intensity on T2WI, and presence of hyperintense areas on T1WI were significant predictors in the unenhanced-MRI-based model. Presence of hyperintensity on T1WI, contrast defect area volume percentage, and degree of enhancement were significant predictors in the enhanced-MRI-based model. The sensitivity/specificity of unenhanced MRI were 87/73 and 87/70% according to reviewer 1 and 2, respectively. The sensitivity/specificity of the enhanced-MRI-based model were 87/70% according to both reviewers. CONCLUSIONS: Our diagnostic models can differentiate carcinosarcoma from carcinoma of the uterus with high sensitivity and moderate specificity.

Multiparametric MRI for differentiation of borderline ovarian tumors from stage I malignant epithelial ovarian tumors using multivariate logistic regression analysis.

OBJECTIVE: To assess the value of contrast-enhanced MRI, apparent diffusion coefficient (ADC) measurement, and CA-125 measurement for differentiating borderline ovarian tumors (BOTs) from stage I malignant epithelial ovarian tumors (MEOTs). MATERIAL AND METHODS: This retrospective study included 43 patients with BOTs and 43 patients with stage I MEOTs who underwent contrast-enhanced MRI with DWI and CA-125 analysis. Two radiologists evaluated the MRI findings in consensus. Univariate and multivariate analyses were performed to detect the best predictor variables for MEOTs. RESULTS: Mixed cystic/solid and predominantly solid appearances, as well as thickened irregular septa, were more frequent in MEOTs. A papillary architecture and internal branching (PA&IB) pattern was more frequent in BOTs. MEOTs had thicker walls and septa, larger solid components, and higher CA-125 values. The mean ADC value of solid components (ADCmean) and minimum ADC value of whole lesions (ADCmin) were lower in MEOTs. Multivariate analysis revealed that ADCmin and maximum diameter of the solid components were independent indicators of MEOTs with an AUC, sensitivity, and specificity of 0.86, 81%, and 84%, respectively. CONCLUSION: ADCmin and maximum diameter of solid components were useful for differentiating BOTs from MEOTs.

[Physical characteristics of anti-scatter grids according to old and new JIS standards].

JIS Z 4910 (anti-scatter grids) of the JIS standards was revised in 2000. Major points of revision were the provision of general-purpose and mammographic anti-scatter grids and changes in the diameter of the measuring field and difference in the manufacturing allowance. We measured the physical characteristics (grid selectivity, contrast improvement ratio, and grid exposure factor) of [general-purpose anti-scatter grids] referring to the methods of measurement [JIS Z 4910:2000] and [JIS Z 4910:1983] using an inverter-type high-voltage generator. Physical characteristics indicated a lower value for [JIS Z 4910:2000] than for [JIS Z 4910:1983]. [JIS Z 4910:2000] was able to measure primary radiation and scattered radiation more accurately than [JIS Z 4910:1983] because of the diameter of the measuring field and the measurement arrangement. Moreover, the physical characteristic values were influenced by radiation quality, e.g., differences in high-voltage generators. In the method of measuring stipulated by JIS, strict conditions regarding the arrangement of the measurement tools and the stability and other factors of the power output of the X-ray generator are provided for the type approval test conducted by the manufacturer.